The present invention relates to injection or transfer molding equipment and particularly to an adapter for use with low viscosity polymeric material, sometimes known as "liquid polymers."
There are presently known numerous chemically different types of polymer systems which are commonly molded by means of injection molding or transfer molding equipment. Most of these polymer systems, whether thermoset or thermoplastic, are at the time of introduction into the mold relatively viscous materials. As a result substantial pressures are required in the mold in order to completely fill the mold cavities with such materials. Further, it is also known that many of these conventional types of polymers require several compounding steps in order to add desired catalysts, fillers, or other additives. More recently, several types of multiple polymers have been produced in a low viscosity or so-called liquid form. These liquid systems allow elimination of much of the flash in molding and simplify design of mold runners as well as eliminating substantial compounding equipment prior to molding. For example, such liquid polymers have been suggested in epoxy formulations, silicone rubber formulations and other organic polymers. While specialized equipment has been developed for molding such liquid systems it is desirable, because many manufacturing facilities already have equipment for molding more viscous types of polymers, to provide an adapter for use with existing molding equipment so that the new types of polymers can be utilized without great expense being incurred. It is toward this adaptation that the present invention is directed.